Luke Weaver’s pitching muse in Yoshinobu Yamamoto could be the Dodgers’ downfall

MLB pitchers are a different breed, to put it as kindly as possible. They're weird and they nitpick every small thing about every little thing they do. A lot of them have strict routines and superstitions they follow to a tee. It's part of what makes baseball so special.

They will hyperfixate on mechanics until everything is perfect. They will try just about every pitch grip under the sun until they find the position, finger pressure and release that helps them obtain the movement profile they're searching for.

And like many athletes, a lot pitchers are also very studious of their peers. In fact, one of the most important pitchers on the New York Yankees' World Series roster has one of the most important pitchers on the Los Angeles Dodgers' World Series roster to thank for the offseason shift that gave him a career resurgence.

According to FanSided MLB Insider Robert Murray, Yankees breakout reliever Luke Weaver told him just how much he studied Yoshinobu Yamamoto's mechanics—and how they improved his game. Now the two will meet in the World Series.

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Luke Weaver attributes some of his mechanical changes to Dodgers' RHP Yoshinobu Yamamoto

One year ago, Luke Weaver had a typical leg kick in his delivery. But this year, Weaver developed more of a hybrid slide-step motion with his leg kick—one that is shockingly similar to Dodgers' star righty, Yoshinobu Yamamoto.

The breakout Yankees' reliever told Murray that he used Yamamoto's mechanics as a "cool template" when re-designing his own leg kick and corresponding mechanics. "He changed, and he kind of simplified it himself. [I thought], how is he doing it? How is he getting to those physical spots in his mechanics? And do they work? Do they work for me? How does that look? Now I have to figure out what's me."

"And of course, the world didn't know what I was doing—I was, you know, at my house, in my garage doing my thing. But it was a really cool template. It was a cool template to see how efficiently he was working and how it worked for him," Weaver said.

The difference between Weaver's old and new mechanics

It's quite a stark difference. It follows an almost identical path that Yamamoto's mechanical journey took. But for Weaver, it was all about simplifying in order to get to certain physical positions that work for his body.

"I had made the change to kind of simplify the leg kick," Weaver said. "And then I saw he [Yamamoto] signed with the Dodgers shortly after. And then we really started to see his mechanics. We really started to see something different."

Weaver studied his pitching motion for solid, subtle information. But was cautious to compare himself too much to Yamamoto. "We don't move the same ways. And he's a freak athlete. He's got a lot of things that I can't do—like handstands."

How did Weaver pull off such a drastic turnaround?

Weaver went beyond the slide step in the stretch, what Yamamoto does. Instead of bringing his leg all the way up like a traditional leg lift in the windup, Weaver uses the hybrid slide step. It’s the simplicity of the slide step combined with the ability to create momentum down the mound that works so well for him.

"The wind up was about creating momentum and finding a way to still create power while moving down the mound. So he was really the only guy that I was seeing doing that," Weaver told Murray this week.

The change in mechanics was immediately seen. In 2023, Weaver posted a 6.40 ERA and a 1.58 WHIP in 123.2 innings. He struck out less than a batter an inning and surrendered more than 11 hits per nine innings. In 2024, Weaver posted a 2.89 ERA and a 0.93 WHIP in 84 regular season innings. He struck out 11 batters per nine innings and surrendered less than six hits per nine innings.

These mechanical changes aren't the only reason that Weaver made such a huge jump in production year over year. Some of his improvements came switching from starting to relieving. Some of his improvements can be attributed to his pitch selection—he completely eliminated the use of his slider and sweeper, opting for a shorter cutter this season.

But it's impossible to talk about Weaver's incredible improvements from 2023 to 2024 without mentioning his mechanical changes. And it's impossible to talk about his mechanics without mentioning the "cool template" of Yamamoto's pitch that helped Weaver adjust his own.

Weaver took notes from Yamamoto to improve his game. Now the two will meet in the World Series.